Patients with diabetes often suffer from undue infection. Juvenile diabetes (insulin-dependent diabetes mellitus - IDDM) is one form of diabetes which affects mainly children and young adults. Some of these young diabetics are known to have particular difficulty in controlling their diabetes and consequently have more complications of diabetes. One of the complications, which precipitates the so-called "diabetic ketoacidoses" is infection; some overt, others hidden unnoticed. We have found that more than 20% of young adult (12 years or older) diabetics have periodontal infection with bone loss (jaw bone) demonstrable X-ray examination. The onset of the periodontal complication appears to coincide with puberty, related to poor dental hygiene and to poor control of their diabetes. We plan to examine further the exact nature of the periodontal complications in our juvenile diabetes patients with regard to: 1) What is the natural course of the development of the periodontal disease, a longitudinal study? 2) What microbial agent is responsible for the development of the infection? 3) How can these lesions be treated? 4) How can these complications be prevented? 5) What defect in immunological, host defense mechanism can be associated with the development of periodontal complication?